Looks like the avr/iom328p.h file provided with the AVR-GCC compiler doesn't agree with the datasheet. In the datasheet, Reset is VectorNo. 1. In the definitions file Reset is Vector 0.
#define TIMER2_COMPA_vect_num 7
#define TIMER2_COMPA_vect _VECTOR(7) /* Timer/Counter2 Compare Match A */
#define TIMER2_COMPB_vect_num 8
#define TIMER2_COMPB_vect _VECTOR(8) /* Timer/Counter2 Compare Match A */
#define TIMER2_OVF_vect_num 9
#define TIMER2_OVF_vect _VECTOR(9) /* Timer/Counter2 Overflow */